Journal of Volcanology and Geothermal Research最新文献

{"title":"Rootless littoral hydrovolcanic explosions and deposits, 6 April 2007, Piton de la Fournaise, La Réunion Island","authors":"Daniele Vergani ,&nbsp;Jocelyn McPhie ,&nbsp;Rebecca Carey ,&nbsp;Andrea Di Muro","doi":"10.1016/j.jvolgeores.2025.108412","DOIUrl":"10.1016/j.jvolgeores.2025.108412","url":null,"abstract":"<div><div>The April 2007 basaltic eruption of Piton de la Fournaise began on 2 April at Piton Tremblet on the eastern flank of the volcano, 7 km from the summit. Vigorous fountains fed aphyric lavas that flowed another 3 km then entered the ocean. During the next few days, the olivine content of the lavas increased and by 5 April, the lavas were oceanite with ∼30 vol% olivine crystals. On 6 April, following a significant increase in lava discharge, spectacular hydrovolcanic explosions occurred where the lava in the main channel entered the ocean. Throughout the day, a sustained steam plume, vertical pyroclastic plumes, base surges and tephra jets were generated by the explosions. The products formed a nested littoral cone at the coast that was partly destroyed and almost entirely covered by subsequent lavas. Although lavas of oceanite composition continued to enter the ocean for the next 24 days, the hydrovolcanic explosions ceased after one day. One 7-m-thick exposure of the littoral cone studied in 2013 comprises bedded, poorly sorted combinations of glassy ash and vesicular lapilli and bombs. Three facies have been identified and interpreted to be deposits from base surges, fall and tephra jets. The explosive lava-water interaction coincided perfectly with a period of elevated discharge at Piton Tremblet on 6 April; the discharge rate subsequently declined. The Piton de la Fournaise 2007 littoral cone resembles historic ‘a‘ā-fed littoral cones on Hawaii. On Piton de la Fournaise, lava entering the ocean at high flow rate or following an increase in discharge ought to be considered potentially hazardous for rootless littoral hydrovolcanic explosions.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"466 ","pages":"Article 108412"},"PeriodicalIF":2.4,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical survey of thermal springs from the Atacama region, northern Chile","authors":"Manuel Inostroza ,&nbsp;Yazmin Godoy ,&nbsp;María Donoso-Peña ,&nbsp;Franco Tassi ,&nbsp;Felipe Aguilera ,&nbsp;Francesco Capecchiacci ,&nbsp;Andrea Luca Rizzo","doi":"10.1016/j.jvolgeores.2025.108411","DOIUrl":"10.1016/j.jvolgeores.2025.108411","url":null,"abstract":"<div><div>This work presents the chemical and isotopic (δ¹⁸O–H₂O and δD–H₂O) composition of five thermal areas from the Atacama region (northern Chile), namely Laguna Verde, Juncalito, Termas de Rio Negro, Panteón de Aliste, and Salar de Piedra Parada. The chemical and isotopic (³He, ⁴He, δ¹³C–CO₂, and δ¹³C–CH₄) composition of gases bubbling from Juncalito is also reported. This work aims to (i) constrain the origin and physicochemical processes controlling the chemical and isotopic composition of bubbling gases and (ii) estimate the equilibrium temperatures of hydrothermal reservoirs. The thermal springs are fed by meteoric waters whose chemistry, during the underground circulation, is mainly controlled by water-rock interaction involving volcanic rocks and volcano-sedimentary sequences. Notable Li, B, and As enrichments are recognized, likely related to the leaching of hydrothermally altered andesitic to rhyolitic rocks and the presence of sedimentary sequences, distinctly below the Claudio Gay Cordillera. The ³He/⁴He ratios (∼1.4–1.5 Ra), within the range of the typical values for low-temperature hydrothermal gases from the Central Volcanic Zone, likely represent a mixture of an atmospheric endmember mixed with a differentiated cooling magma residing within the crust for a long time. The δ¹³C-CO₂ values suggest a dominant crustal CO₂ source with a minor (1 %) mantle contribution. Chalcedony geothermometer provides reservoir temperatures up to 91 and 88 °C in Termas de Rio Negro and Laguna Verde, respectively. Further geophysical and geostructural investigations are recommended to constrain the source of heat in the Laguna Verde area, especially considering the presence of the quiescently degassing Ojos del Salado volcano.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"467 ","pages":"Article 108411"},"PeriodicalIF":2.3,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144721364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calcite priming of a hydrothermal eruption at South Orakonui, Ngā Tamariki Geothermal Field, New Zealand","authors":"Mark P. Simpson ,&nbsp;Michael D. Rosenberg ,&nbsp;Cristian Montanaro ,&nbsp;Duncan J. Graham","doi":"10.1016/j.jvolgeores.2025.108409","DOIUrl":"10.1016/j.jvolgeores.2025.108409","url":null,"abstract":"<div><div>On the 19th of April 2005, a small hydrothermal eruption took place at the Ngā Tamariki Geothermal Field, New Zealand. The 2005 eruption at South Orakonui cut through an existing hydrothermal eruption crater created in 1948 and ejected mud and rocks (breccia) up to 110 m from the vent. The breccia deposit thins exponentially from 2 to 3 m thick on the crater rim to &lt;0.3 m approximately 70 m to the east with an estimated volume of ∼3.7 to ∼4.9 × 10³ m³ (dependent on crater rim thickness). Polymictic ejecta include rock fragments of pumice, tuff, cemented sand/pebbles, and mudstone that are supported in an unconsolidated mud-dominated matrix. Minor clasts of coarse sand to pebble conglomerate are preserved due to cementation by calcite or alternatively in fewer samples by opal/quartz. Included in the breccia are rare platy calcite vein fragments (up to 19 cm in length); the bladed crystal morphology indicating formation from a boiling fluid. Based on the measurement of fluid inclusions in platy calcite crystals the median homogenisation temperatures of 132° to 144 °C indicate that these vein fragments were sourced from 20 to 33 m below the water table. A model for the 2005 hydrothermal eruption is proposed in which pressurisation was due to the sealing of pores and fractures by calcite deposited from a near boiling-to-boiling fluid. Lesser deposition of opal/quartz by cooling contributed to the sealing. The 2005 eruption was preceded by gradual changes in surface thermal features over 12 years seen by the declining discharge of two springs, plus the short-lived appearance then demise of another. These changes are interpreted to reflect gradual and imperfect subsurface sealing by calcite and minor opal/quartz. The eruption trigger is not known and could be due to simple over pressurisation, a slight decline in the groundwater level (&lt;1 m), or seismic activity. Priming of an eruption by calcite sealing has not been reported for other hydrothermal eruptions in New Zealand and globally is rare. Calcite sealing may have been significant in other hydrothermal eruptions but not recognised since calcite is easily destroyed by continuing thermal activity (steam, acid condensates) and/or by weathering as is currently taking place at South Orakonui.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"466 ","pages":"Article 108409"},"PeriodicalIF":2.4,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144662742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Volcano Seismic Event Recognition and OOD Detection using Multi-Representation Deep Learning: Insights from Nevados del Chillán","authors":"Camilo Espinosa-Curilem ,&nbsp;Daniel Basualto ,&nbsp;Millaray Curilem ,&nbsp;Fernando Huenupan","doi":"10.1016/j.jvolgeores.2025.108406","DOIUrl":"10.1016/j.jvolgeores.2025.108406","url":null,"abstract":"<div><div>Deep learning models have significantly improved automatic volcano-seismic event classification but struggle with previously unseen signals due to their closed-set assumption, leading to confident misclassification of external events, as seismic sensors often capture non-volcanic movements. This study ad- dresses this limitation by integrating a simple and computationally lightweight K-Nearest Neighbors (KNN)-based Out-of-Distribution (OOD) detection mod- ule into a CNN classifier, dividing the classification problem in a trade-off between the classification of in-distribution volcanic events (ID) and the iden- tification of non-volcanic events (OOD). We explored an input representation that integrates waveforms and frequency spectrum alongside spectrograms using Class Activation Maps to evaluate their impact in learning. We found that combining waveforms with spectrograms improves ID performance as well as OOD sensitivity. Experimental results on a Nevados del Chillán Vol- canic Complex database show that our approach reaches a mean accuracy of 93.5 % for non volcanic classes (correctly classified as OOD) maintaining 84.3 % for the classification of volcanic classes (ID) compared to 73.8 % with the only-spectrogram representation. These findings demonstrate that combining multi-domain feature representations with a lightweight KNN-based OOD module raises mean OOD accuracy from 73.8 % to 93.5 % while pre- serving an 84.3 % ID F1-score, thereby improving the reliability of automated volcano-seismic monitoring and provides evidence that the approach could be incorporated into deployable, multi-volcano systems after further validation on additional sites.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"466 ","pages":"Article 108406"},"PeriodicalIF":2.4,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144662741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fracture dynamics and topographic controls at Mount Thorbjörn during the Svartsengi 2023–2024 volcanic unrest, Iceland","authors":"Maria Hurley ,&nbsp;Nicolas Oestreicher ,&nbsp;Alina V. Shevchenko ,&nbsp;Gregory P. De Pascale ,&nbsp;Magnús T. Gudmundsson ,&nbsp;Egill Á. Gudnason ,&nbsp;Gylfi P. Hersir ,&nbsp;Benjamin F. De Jarnatt ,&nbsp;Alea Joachim ,&nbsp;Joël Ruch ,&nbsp;Fabio L. Bonali ,&nbsp;Thomas R. Walter","doi":"10.1016/j.jvolgeores.2025.108407","DOIUrl":"10.1016/j.jvolgeores.2025.108407","url":null,"abstract":"<div><div>Regions with complex topography experience varying degrees of deformation during volcano-tectonic events. Few studies have investigated the relationship between topography and fracturing in detail, and therefore insights into this interplay are limited. In this work, we analysed deformation patterns during the 2023–2024 volcanic unrest on the Reykjanes Peninsula, Iceland, focusing on the dyke-induced graben episode of 10 November 2023. Our study is centred on Mount Thorbjörn, the ∼200 m high glaciovolcanic edifice located on the western shoulder of the graben. We collected four drone photogrammetric datasets between 2022 and 2024, covering different phases of the volcanic unrest. By comparing cm-resolution orthophotos and digital elevation models, we identified transtensional reactivation of pre-existing grabens, with normal offsets reaching 80 cm and 20–30 cm of dextral strike-slip. Larger offsets in the south-eastern sector of the mountain suggest tilting in line with the regional deformation trend, although the displacement in the mountain was high compared to lower adjacent regions. Orthophoto comparison revealed ∼9 km of new cumulative surface fractures and over 200 sinkholes, with 88 % of the fractures and 59 % of the sinkholes formed during the November 2023 graben event. Statistical analyses indicate a strong topographic influence on fracture development. Fracture density increased with elevation, clustering around local peaks. Our results provide a conceptual model for fracture dynamics in complex topographies during volcanic unrest, where higher elevations are more sensitive to deformation, leading to greater damage.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"466 ","pages":"Article 108407"},"PeriodicalIF":2.4,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of local topography/structure on lava flow direction: A view from Ananthagiri Hills from Deccan Basalts, India","authors":"A.V. Satyakumar ,&nbsp;Antara Mrinal ,&nbsp;A.K. Ojha ,&nbsp;J. Ashok ,&nbsp;M. Venkateshwarlu","doi":"10.1016/j.jvolgeores.2025.108408","DOIUrl":"10.1016/j.jvolgeores.2025.108408","url":null,"abstract":"<div><div>Deccan Trap lavas may have erupted through multiple centers, the most prominent of which may have been a shield volcano-like structure in the Western Ghats. The lava transportation and emplacement mechanism provides crucial information on the source and how lava is associated with crustal rocks. Here, we present the results of Anisotropy of magnetic susceptibility (AMS), rock magnetism, and petrology to understand the lava flow directions of Deccan basalts at Ananthagiri Hills. We collected 48 oriented block rock samples from 6 sites and prepared 432 specimens for the detailed investigation. Rock magnetic study indicates that the Pseudo-single domain of titanomagnetite is the primary carrier magnetic mineral. Under the microscope, the volcanic rocks of the Ananthagiri predominantly contain plagioclase and pyroxene phenocrysts that are surrounded by plagioclase, pyroxene, and other opaques, including magnetite and titanomagnetite in the matrix. The AMS principal susceptibility axes are closely clustered with well-developed magnetic lineation and foliation. The magnetic lineation (K₁) aligns best with microscopic flow indicators along NE-SW, indicating the lava flow direction. The pole of magnetic foliation (K₃) clustered at the center with an almost sub-vertical direction, whereas K₁ and K₂ are shallow plunging NE-SW and NW-SE directed, respectively. The degree and shape parameters indicate a mixed oblate and prolate nature; most sites are oblate. Based on all these observations, it is inferred that the local paleo-topography and structures before the Deccan eruption at ∼65 Ma in the basement Dharwar craton affect the lava flow in the study region with an anomalous SW-directed flow.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"466 ","pages":"Article 108408"},"PeriodicalIF":2.4,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144596279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global sensitivity analysis of models for volcanic ash forecasting","authors":"Emmy Scott,&nbsp;Melody Whitehead,&nbsp;Stuart Mead,&nbsp;Mark Bebbington,&nbsp;Jonathan Procter","doi":"10.1016/j.jvolgeores.2025.108393","DOIUrl":"10.1016/j.jvolgeores.2025.108393","url":null,"abstract":"<div><div>Volcanic ash is a widespread and destructive volcanic hazard. Timely and accurate forecasts for ash deposition and dispersal help mitigate the risks of volcanic hazards to society. Producing these forecasts requires numerous simulations with varying input parameters to encapsulate uncertainty and accurately capture the actual event to deliver a reliable forecast. However, exploring all possible combinations of input parameters is computationally infeasible in the lead up to an eruption. This research explores the input space of two volcanic ash transport and dispersion models, Tephra2, which is based on a simplified analytical solution, and Fall3D, which is a computational model based on more general assumptions, in the context of forecasting an unknown future eruption. We use the exemplar of Taranaki Mounga (Mount Taranaki), Aotearoa New Zealand, which has an estimated 30% to 50% chance of an explosive eruption in the next 50 years. We statistically determine how much each input parameter contributes to model output variance through a global sensitivity analysis via Sobol’ indices and the extended Fourier Amplitude Sensitivity Test (eFAST). Our findings show that grain size distribution, diffusion, plume shape, and plume duration (Fall3D only) have a substantial first-order impact on model output variance. In contrast, mass, particle density, and plume height have minimal impact in the first-order but become influential when considering parameter-parameter inter-relationships (total-order). The results not only enhance our understanding of model sensitivities but also point to improved efficiency in forecasting efforts.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"466 ","pages":"Article 108393"},"PeriodicalIF":2.4,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144655708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magma–carbonate country rock interaction can provide H2O during magma ascent: Results from fluid and melt inclusions in skarn xenoliths from Breccia Museo, Campi Flegrei (Southern Italy)","authors":"Annamaria Lima ,&nbsp;Giovanni Macedonio ,&nbsp;Rosario Esposito ,&nbsp;Harvey E. Belkin","doi":"10.1016/j.jvolgeores.2025.108405","DOIUrl":"10.1016/j.jvolgeores.2025.108405","url":null,"abstract":"<div><div>In this paper, the results of a study on fluid inclusions (FIs) and melt inclusions (MIs) hosted in skarn-bearing minerals sampled in the Breccia Museo deposits at Campi Flegrei (Southern Italy) are reported and discussed to investigate magma‑carbonate interactions. The Campi Flegrei shallow magma chamber fluid environment has been interpreted as similar to that documented in the magmatic-hydrothermal systems associated with porphyry copper deposits. Skarns form along the top and sides of the magma chamber in the brittle-plastic transition zone, where magmatic fluids accumulate through magmatic vesiculation and magma interacts with carbonate country rocks. Melt inclusions, here named saline‑carbonate-melt inclusions (SCMI), trapped in olivine, provide crucial insights into the melt that forms in this setting. Heating/cooling experiments on SCMI show that they trapped a homogeneous melt that, on cooling, undergoes instantaneous unmixing, leading to the formation of three immiscible liquids: silicate, carbonate and hydrosaline (brine). The melt behavior on micrometer scales, in SCMI, is assumed reproduces what happens on a large scale, this means that in the transition zone melt remains homogeneous at <em>T</em> &gt; 980 °C and instantly unmixes when cooled below 790 °C. To account for the instant unmixing and the absence of CO₂ in SCMI shrinkage bubbles, we propose that at high T the reaction of CaCO₃ with H₂O (by magma second boiling) produces Ca(OH)₂ and H₂CO₃ that dissolve in the homogeneous melt and prevent the formation of CO₂. At lower T by unmixing, CaCO₃ re-forms, releasing H₂O. The carbonate plays an essential role as it removes at high T, one mole of CO₂ from homogeneous melt and simultaneously releases two moles of H₂O at lower T when unmixing occurs. We argue that, during magma ascent, this water supply can facilitate the upward propagation of dyke to the surface and can enhance explosivity, during an ongoing eruption.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"466 ","pages":"Article 108405"},"PeriodicalIF":2.4,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of cooling rate on rheology and emplacement dynamics of basaltic lavas: Insights from the January 2024 Sundhnúksgígar eruption (Iceland)","authors":"Fabrizio Di Fiore ,&nbsp;Alessandro Vona ,&nbsp;Danilo Di Genova ,&nbsp;Alberto Caracciolo ,&nbsp;Alessio Pontesilli ,&nbsp;Laura Calabrò ,&nbsp;Gabriele Giuliani ,&nbsp;Silvio Mollo ,&nbsp;Dmitry Bondar ,&nbsp;Manuela Nazzari ,&nbsp;Claudia Romano ,&nbsp;Piergiorgio Scarlato","doi":"10.1016/j.jvolgeores.2025.108400","DOIUrl":"10.1016/j.jvolgeores.2025.108400","url":null,"abstract":"<div><div>The 2023–2024 eruptions at Sundhnúksgígar in Iceland produced tholeiitic basaltic lavas that traveled at high velocities, affecting vast areas. Under such conditions, disequilibrium crystallization can play a fundamental role in modulating the lava flow dynamics and inundation capacity. To investigate this phenomenon, we carried out a comprehensive rheological characterization of the Sundhnúksgígar basalt, analyzing both the liquid phase and the crystal-bearing suspensions under disequilibrium conditions (cooling rates ranging from 0.1 to 10 °C/min) and near-equilibrium conditions (at fixed temperatures between 1242 and 1180 °C). Our results show that the cooling rate critically influences the extent and timescale of disequilibrium crystallization, thereby shaping the rheological evolution of the melt, leading to distinct deformation response of the crystal-bearing magmatic suspension. Compared to other basalts erupted worldwide, the Sundhnúksgígar melt exhibits two main features: i) an exceptionally low rate of viscosity increase induced by crystallization and ii) the ability to crystallize even at the highest cooling rates applied during the experiments. These characteristics may contribute to enhancing the efficiency of external crust formation, limiting heat loss from the inner portion of the lava flow, which consequently cools more slowly. Thermal insulation effects reduce the rate of viscosity increase during lava emplacement, a key factor in determining lava flow inundation potential. Our findings underscore the critical role of disequilibrium crystallization in governing the rheological evolution and emplacement dynamics of basaltic lavas, offering new insights into lava flow behavior.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"466 ","pages":"Article 108400"},"PeriodicalIF":2.4,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144564069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Volcanic history of Gölcük caldera (Isparta, Türkiye) with evidence for a Holocene explosive eruption","authors":"Gökhan Atıcı ,&nbsp;Bjarne Friedrichs ,&nbsp;Mehmet Çobankaya ,&nbsp;Martin Danišík ,&nbsp;Evren Atakay ,&nbsp;Esra Yurteri ,&nbsp;Axel K. Schmitt","doi":"10.1016/j.jvolgeores.2025.108403","DOIUrl":"10.1016/j.jvolgeores.2025.108403","url":null,"abstract":"<div><div>Modern Lake Gölcük near the city of Isparta partially fills a caldera that is the focal point of protracted alkaline, potassic–ultrapotassic volcanism in southwestern Anatolia. Because of Gölcük's proximity to a major regional urban center, and field indications for far-reaching pyroclastic density currents (PDC) erupted from this caldera, improved constraints on eruptive recurrence and timing are required. Through field work and combined U<img>Th and (U<img>Th)/He zircon geochronology, the duration of known volcanism at Gölcük has been extended, both to older and, importantly, to younger ages than previously reported. Early activity in the Late Miocene–Pliocene (Stage 1, 6.0–4.2 Ma) was mostly effusive, whereas explosive activity started in the Early Pleistocene (Stage 2, 2.2–1.8 Ma) forming nine PDCs of the Serençay valley ignimbrite sequence. Following a hiatus, PDC and fallout emplacement resumed during Stage 3 (520–480 ka) and Stage 4 (150 ka), with the modern caldera likely being the result of the Stage 4 Çay ignimbrite eruption. U<img>Th zircon crystallization ages of antecrysts, especially in Stage 4 and 5 pumice, clearly implicate Gölcük as the source of the Stage 2 and 3 explosive eruptions. Stage 5 includes effusive activity and dome formation, but also at least four explosive eruptions starting at c. 24 ka. The discovery of the here termed Isparta ignimbrite, which erupted from Gölcük caldera at 10.7 ± 0.7 ka (2 σ uncertainty), identifies it as an active volcano. Frequent eruptions at recurrence intervals of 4–5 ka during the Late Pleistocene–Holocene transition warrant future research regarding its hazard potential. This also implies that Gölcük may have erupted distal tephra markers for this climatically important interval.</div></div>","PeriodicalId":54753,"journal":{"name":"Journal of Volcanology and Geothermal Research","volume":"466 ","pages":"Article 108403"},"PeriodicalIF":2.4,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}